Most oil producing subterranean formations are characterized by pressurized gas. In some parts of the work hydrocarbon bearing formations have pressures sufficient to force liquid hydrocarbons (crude oil) to the earth's surface. In other parts of the world, the gas pressure is not sufficient to force liquid hydrocarbons to the earth's surface. However, in such formations, the presence of gas is nevertheless important since in many formations a gas drive is required to move liquid hydrocarbons from within the formation to the site of a producing well or wells.
As crude oil is extracted from a subterranean reservoir, the reservoir gas pressure decreases. As the gas pressure decreases, crude oil production rates usually fall. For these and other reasons, it has been found desirable in producing many subterranean formations to maintain gas pressure within the formations.
The characteristics of gas injected into a well can be critical. Free oxygen contained in injected gas can cause plugging of formations. Further free oxygen can result in bacteria growth that can plug a producing formation, and corrode tubulars in the producing well.
Ideally, gas injected into a reservoir to augment the production of liquid hydrocarbons should be oxygen-free. Therefore, when treating gas prior to injection, a most important step is to remove substantially all free oxygen.
The present invention provides a process for generating substantially oxygen-free exhaust gas that is particularly useful for injection into hydrocarbon bearing formations.
Example of the use of exhaust gas from an engine for industrial purposes and examples of the use of exhaust gas to augment liquid hydrocarbon production can be found in the attached Information Disclosure Statement.